1. Field of the Invention
The present invention relates to an apparatus and a method for removing a sterilizing liquid from a packing material web in a filling/packing machine or other such machine which manufactures liquid packing containers from the web, and more particularly to an apparatus and a method of removing sterilizing liquid from the web in the filling/packing machine or other such machine which manufactures the liquid packing containers by a method comprising the steps of: sterilizing the packing material web having a sealing tape adhered to its side end portion by soaking the web in the sterilizing liquid such as aqueous hydrogen peroxide or the like, removing the sterilizing liquid from the web, gradually forming the web into a tubular shape and adhering its longitudinal both ends to each other while filling a liquid inside, then hermetically sealing and cutting the web at the length corresponding to one container, and shaping the web.
2. Description of Related Art
A filling/packing machine which manufactures liquid packing containers from a packing material web usually has a sterilizing liquid tank for sterilizing the web, and the web sterilized by being soaked in the sterilizing liquid tank is taken out of the sterilizing liquid tank and then the sterilizing liquid which adheres to the web is removed. As the apparatuses for removing the sterilizing liquid from the web, there are known apparatuses such as: an apparatus in which driblets on the surface of a web are squeezed while the web is made to pass through a pair of rubber rollers called squeeze rollers which can rock freely, an apparatus in which a hot and high-speed air is blasted at a web from an air knife and driblets on the surface of the web are blown off (Japanese Patent Publication No. 44-20556), an apparatus in which driblets on the surface of a web are evaporated, while the web is made to pass through a narrow gap between two partitioned rooms, and by blasting a hot and high-speed air into one of the rooms during the passing (Japanese Laid-Open Patent Application No. 8-58740), and an apparatus in which the above-stated methods are used together.
Some modifications have been made to the above-mentioned apparatuses for removing the sterilizing liquid from the web. In Japanese Laid-Open Patent Application No. 10-114311, there is a description of a web sterilizing liquid remover having a sterilizing liquid tank, a web transfer means for introducing a web into the sterilizing liquid tank, soaking the introduced web in a sterilizing liquid in the sterilizing liquid tank, and then taking out the web from the sterilizing liquid tank, and a pair of squeeze rollers disposed so that it can open and close while sandwiching the transfer route of the web taken out of the sterilizing liquid tank therebetween, where one of the two squeeze rollers is arranged to be a fixed roller and the other is arranged to be a movable roller in order to locate the both rollers precisely at a closed position. Further, in Japanese Laid-Open Patent Application No. 11-348937, there is a description of a method of removing a liquid on the surface and in a recess of the packing material and a liquid remover, where a blast nozzle for blasting an air only at the recess is disposed on this side of a squeeze roller for conveying the packing materials, at the position where the recess of the packing material passes, and an air knife section for blasting the air at the whole width of the packing materials is disposed behind the squeeze roller, and the air knife and a blast pipe having the blast nozzle are connected communicatively, consequently, a sterilant in the recess of the packing material is removed concentratedly and the sterilant adhering to the whole surface of the packing materials can be removed efficiently and uniformly by the following blast from the air knife section.
Objects of the Invention
In manufacturing liquid beverages which are packed in paper containers for long-term storage from a packing material web, an oxygen-impermeable or a water-impermeable sealing tape is adhered to the side end portion of the web in order to prevent an air from permeating into the container through an end face of the web in contact with the content of a vertical heat-sealing portion where the both longitudinal ends of the web are adhered to each other by heat-sealing, or to prevent the content from permeating through an end face of the web in contact with the content of a vertical heat-sealing portion adhered. The packing material web having the sealing tape adhered to its side end portion has been soaked in the sterilizing liquid in the sterilizing liquid tank, and then taken out of the sterilizing liquid tank, and the sterilizing liquid adhering to the surface of the web has been removed and dried by a conventional sterilizing liquid remover with a squeeze roller and an air knife. It has been found that, however, because of high transfer speed of the web in recent high-speed filling/packing machines, the conventional sterilizing liquid remover cannot remove/dry the sterilizing liquid sufficiently at a step portion formed by the sealing tape and the web which forms the container""s interior side, and therefore, a problem that the sterilizing liquid remains at the step portion has arisen. An object of the present invention is to provide a sterilizing liquid remover and a method of removing the sterilizing liquid which can easily remove/dry the sterilizing liquid which remains at the step portion formed by the sealing tape and the web which forms the container""s interior side in a packing material web having a sealing tape adhered to its side end portion.
Means to Attain the Object
The inventors of the present invention conducted diligent research aimed at attaining the above-mentioned object. First, as a method which does not change the design of the conventional sterilizing liquid remover, some experiments, where the hardness of surface material rubber of the squeeze roller was changed to be softer, the amount of the wind from an air knife was increased, or the temperature of the wind from the air knife was raised, were conducted. However, satisfactory results could not be obtained. Next, as a method which partially changes the design of the conventional sterilizing liquid remover, an experiment using a second air knife having a small and round opening which can dry and remove the sterilizing liquid remaining at the step portion formed by the sealing tape and the web which forms the container""s interior side locally was conducted. It was found that the sterilizing liquid remaining at the step portion could be removed to some extent by using the second air knife together, however, a phenomenon, where the sterilizing liquid blown by the second air knife forms driblets and adheres to or trickles down on the surface of the web away from the step portion, was often observed. Though the cause of the phenomenon is unknown, it has been found that it is effective to use the second air knife having a wide opening which covers said step portion laterally, in particular, to dispose the second air knife between a pair of air knives and squeeze rollers for removing the sterilizing liquid brought about by the phenomenon, and the present invention has been completed.
The present invention relates to a sterilizing liquid remover characterized in comprising: squeeze rollers for squeezing driblets on the surface of a web, disposed such that they can open and close while sandwiching the transfer route of the web having a sealing tape adhered to its side end portion therebetween; first air knives being able to blast a heated air at least to the whole width of the web which forms the container""s interior side, disposed downstream of the squeeze roller in a web transfer direction; a second air knife being able to blast the heated air at a step portion formed by the sealing tape and the web which forms the container""s interior side, disposed upstream of the first air knife in the web transfer direction (first aspect), the sterilizing liquid remover according to the first aspect, wherein the first air knives are a pair of air knives disposed such that they can open and close while sandwiching the transfer route of the web therebetween (second aspect), the sterilizing liquid remover according to the first and second aspects, wherein the second air knife is disposed between the first air knife and the squeeze roller (third aspect), the sterilizing liquid remover according to any one of the first to third aspects, wherein the second air knife has a wide opening which laterally covers the step portion formed by the sealing tape and the web which forms the container""s interior side (fourth aspect), the sterilizing liquid remover according to anyone of the first to fourth aspects, wherein the second air knife is disposed such that the web heated by the second air knife reaches the first air knife before cooling down (fifth aspect), the sterilizing liquid remover according to any one of the first to fifth aspects, wherein the second air knife is fixed to the same rotary axis as the first air knife which can blast the heated air at the whole width of the container""s interior side of the web (sixth aspect), the sterilizing liquid remover according to any one of the first to sixth aspects, wherein the second air knife and the first air knife which can blast the heated air at the whole width of the container""s interior side of the web are connected communicatively (seventh aspect), and the sterilizing liquid remover according to any one of the first to seventh aspects, wherein driblets on the surface of the web and squeezed by the squeeze rollers are the driblets on the surface of the web which is introduced into a sterilizing liquid tank and soaked into the sterilizing liquid therein, and taken out of the sterilizing liquid tank (eighth aspect).
The present invention also relates to a method of removing the sterilizing liquid characterized by that the heated air is blasted at the step portion formed by the sealing tape and the web which forms the container""s interior side by the second air knife disposed upstream of the web transfer direction of the first air knife in a method of removing the sterilizing liquid comprising the steps of: squeezing the driblets on the surface of the web by the squeeze rollers disposed such that they can open and close while sandwiching the transfer route of the web having the sealing tape adhered to its side end portion therebetween, and blasting the heated air at least at the whole width of the container""s interior side of the web by the first air knife disposed downstream of the web transfer direction of the squeeze roller (ninth aspect), the method of removing the sterilizing liquid according to the ninth aspect, wherein the heated air is blasted at the both faces of the web by the first air knives (tenth aspect), the method of removing the sterilizing liquid according to the ninth to tenth aspects, wherein the heated air at a speed of 15xcx9c25 m/s and with a temperature of 90xcx9c110xc2x0 C. is blasted by the first air knife (eleventh aspect), the method of removing the sterilizing liquid according to any one of the ninth to eleventh aspects, wherein the driblets on the surface of the web are squeezed by the squeeze rollers and then the heated air is blasted at the step portion formed by the sealing tape and the web which forms the container""s interior side by the second air knife (twelfth aspect), the method of removing the sterilizing liquid according to any one of the ninth to twelfth aspects, wherein the heated air is blasted widely and laterally at the step portion formed by the sealing tape and the web which forms the container""s interior side by the second air knife (thirteenth aspect), the sterilizing liquid remover according to any one of the ninth to thirteenth aspects, wherein the web heated by the second air knife is blasted the heated air by the first air knife before cooling down (fourteenth aspect), the method of removing the sterilizing liquid according to any one of the ninth to fourteenth aspects, wherein the heated air at a speed of 18xcx9c28 m/s and with a temperature of 90xcx9c110xc2x0 C. is blasted by the second air knife (fifteenth aspect), and the method of removing the sterilizing liquid according to any one of the ninth to fifteenth aspects, wherein the wind speed of the second air knife is always faster than that of the first air knife (sixteenth aspect).